Placenta previa occurs when the placenta attaches somewhere in the lower segment of the uterus and completely or partially obstructs the cervix or lies in the lower segment near the cervical opening.
Placenta previa is uncommon, occuring in only 3 to 6 of 1000 pregnancies and is probably due to uterine scarring from curretage (scraping of the inside of the uterus) after spontaneous miscarriage, multiple pregnancies, and previous cesarean births. The placenta looks for unscarred segments of the uterus to attach to, which are usually found in the lower segment of the uterus.
If placenta previa is diagnosed after 28 weeks and no bleeding has occurred, you will be most likely be put on bedrest to avoid bleeding. Intercourse is prohibited. Ultrasounds are usually done every 3 to 4 weeks to assess the location of the placenta. If you are 24 or more weeks pregnant, and have had any bleeding, your doctor will probably put you in the hospital for closer observation.
Any bleeding in pregnancy can be very scary, but preterm birth is the greatest danger to the baby with placenta previa, not bleeding. The goal in managing placenta previa is to try to avoid preterm birth. Follow your doctor’s instructions and be patient. In half the cases of placenta previa, delivery can by delayed by as much as 4 weeks to give your baby the best start possible.
Placental abruption is when all or part of the placenta separates from the wall of the uterus before the baby is born. When this happens, there are painful contractions and bleeding. The bleeding can be slight to gushing.
The blood is bright red, which is different from pinkish, mucous bloody show. The uterus contracts frequently (every 1-2 minutes) from the irritation of the abruption and remains firm between the contractions. If you have these symptoms, call your doctor and go right to the hospital, especially if bleeding is heavy.
When you get to the hospital, you’ll be watched closely, and the fetal monitor will evaluate if the bleeding is affecting the baby’s oxygen supply. What your doctor decides to do next depends on how much of the placenta has separated from the wall of the uterus. The doctors and nurses in the obstetrical unit are expert at handling these kinds of problems. You’re in good hands.